Asthma affects 10% of the US population, with 500 annual deaths. About 50% of asthma patients do not take recommended anti-inflammatory medication, fearing side effects, expense, etc. A nondrug alternative treatment with anti-inflammatory effects could protect these patients from exacerbations. A method that dilates the airways may be helpful as a complementary treatment, and may block progression of exacerbations,once started. The purpose of this study is to evaluate the role of heart rate variability biofeedback (HRV-BF) in asthma therapy by examining its effects on airways reactivity and inflammation, two underlying processes thought to be central characteristics of asthma. It will test the efficacy of HRV-BF as either an alternative or complement to inhaled steroid medication. Our previous research found that it decreased asthma symptoms, improved lung function, and decreased number of exacerbations, with decreased amounts of asthma medication. This study will investigate its role as an alternative or complementary treatment for asthma, vis-`- vis inhaled steroids, by studying its effects as an anti-inflammatory and a bronchodilator agent. In an exploratory analysis, we also will estimate its proportional effect compared with a recommended dose of budesonide. To best observe the effects of HRV-BF on airways biology we will study steroid-naove patients with mild to moderate asthma. The primary outcome measure will be airways reactivity, assessed by a methacholine challenge test. A secondary outcome measure will be exhaled nitric oxide, a measure of airways inflammation. Sixty subjects with mild to moderate asthma will each be assigned to one of two groups, one receiving HRV-BF and one receiving a placebo biofeedback condition (PBO-BF). A third group of 38 subjects will receive HRV-BF and one month of a standard inhaled corticosteroid dose (budesonide 720 mcg/day) to allow us to estimate the proportion of budesonide effects produced by HRV-BF. Subjects will receive 10 sessions of HRV or PBO BF training, preceded by a one-month behavioral run-in, to more accurately assess asthma severity and ability to carry out study procedures. The study will take place in two collaborating sites to insure objectivity, expertise, and meeting recruitment goals. The UMDNJ site conducted the original study and has major biofeedback expertise, while the National Jewish Health site is an internationally respected asthma treatment center, with major clinical trials expertise. We will take additional exploratory outcome measures evaluating the effect of HRV-BF on asthma symptoms, pulmonary function (through spirometry and forced oscillation pneumography), asthma quality of life, and psychological stress.